Engineering Commons^™

Modeling Dual Polarization Wireless Fading Channels Using Quaternions, B. J. Wysocki, Tadeusz Wysocki, J. Seberry

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In the letter we describe signal transmitted between two dual-polarized antennas using a quaternion notation. The channel can then be modeled by a single quaternion gain, instead of a matrix of four complex gains as it is done in a classical approach. The model is very useful as it allows for a simple accommodation of any polarization twist between the transmit and receive antennas, as well as, modeling random fading in both polarizations with or without cross-polar scattering.

A Survey On Networking Games In Telecommunications, E. Altman, T. Boulogne, R. El-Azouzi, T. Jiménez, Laura Wynter

Research Collection School Of Computing and Information Systems

In this survey, we summarize different modeling and solution concepts of networking games, as well as a number of different applications in telecommunications that make use of or can make use of networking games. We identify some of the mathematical challenges and methodologies that are involved in these problems. We include here work that has relevance to networking games in telecommunications from other areas, in particular from transportation planning.

Parameter Inference Of Queueing Models For It Systems Using End-To-End Measurements, Laura Wynter, Cathy H. Xia, Fan Zhang

Research Collection School Of Computing and Information Systems

As Information Technology (IT) matures and expands in the scope of available applications, IT systems increase at a fascinating rate in both size and complexity. For example, today, a typical Web service hosting center may have hundreds of nodes and dozens of different applications simultaneously running on it. Each of the nodes in turn has often multiple processors and layered caches. These nodes make use of both local and shared storage systems. The size and complexity of such systems make performance modeling much more difficult, if at all tractable. Detailed modeling, fine tuning and accurate analysis can be carried out …

On The Performance Evaluation Of High-Speed Transport Protocols, Bridget Hillyer

UNF Graduate Theses and Dissertations

As high-speed networks with large bandwidth delay products (BDP) become more common, high-speed transport protocols must be developed that perform well in these contexts. TCP has limitations in high BDP networks. A number of high-speed TCP proposals have emerged, including BIC TCP, High Speed TCP, and H-TCP. XCP is an intraprotocol communication mechanism that promises even greater performance by providing explicit feedback from routers about congestion. It requires changes to routers and end hosts, though, whereas the other experimental protocols only require changes to an end host. We evaluated the performance ofXCP against BIC TCP, High Speed TCP, H-TCP, and …

Design Concepts And Process Analysis For Transmuter Fuel Manufacturing, Georg F. Mauer

Fuels Campaign (TRP)

The safe and effective manufacturing of actinide-bearing fuels for any transmutation strategy requires that the entire manufacturing process be contained within a shielded hot cell environment. To ensure that the fabrication process is feasible, the entire process must be designed for remote operation. The equipment must be reliable enough to perform over several decades, and also easy to maintain or repair remotely. The facility must also be designed to facilitate its own decontamination and decommissioning. In addition to these design factors, the potential viability of any fuel fabrication process will also be impacted by a number of variables, such as …

Efficient Scheduling For Sdmg Cioq Switches, Mei Yang, S. Q. Zheng

Electrical & Computer Engineering Faculty Research

Combined input and output queuing (CIOQ) switches are being considered as high-performance switch architectures due to their ability to achieve 100% throughput and perfectly emulate output queuing (OQ) switch performance with a small speedup factor S. To realize a speedup factor S, a conventional CIOQ switch requires the switching fabric and memories to operate S times faster than the line rate. In this paper, we propose to use a CIOQ switch with space-division multiplexing expansion and grouped input/output ports (SDMG CIOQ switch for short) to realize speedup while only requiring the switching fabric and memories to operate at the line …

A Corpus-Based Concatenative Speech Synthesis System For Turkish, Haşi̇m Sak, Tunga Güngör, Yaşar Safkan

Turkish Journal of Electrical Engineering and Computer Sciences

Speech synthesis is the process of converting written text into machine-generated synthetic speech. Concatenative speech synthesis systems form utterances by concatenating pre-recorded speech units. Corpus-based methods use a large inventory to select the units to be concatenated. In this paper, we design and develop an intelligible and natural sounding corpus-based concatenative speech synthesis system for the Turkish language. The implemented system contains a front-end comprised of text analysis, phonetic analysis, and optional use of transplanted prosody. The unit selection algorithm is based on commonly used Viterbi decoding algorithm of the best-path in the network of the speech units using spectral …

An Ann Based Approach To Improve The Distance Relaying Algorithm, Hassan Khorashadi Zadeh, Zuyi Li

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an artificial neural network- (ANN) based approach to improve the performance of the distance relaying algorithm. The proposed distance relay uses magnitudes of voltages and currents as input signals to find fault locations. In this approach, an ANN has been included in the protection algorithm as an extension of the existing methods, which improves the reliability of the protection operation. The design procedure of the proposed relay is presented in detail. Simulation studies are performed and the influence of changing system parameters, such as fault resistance and source impedance, is studied. Performance studies show that the proposed …

Sturm-Liouville Equation: The Bridge Between Eigenvalue And Green's Function Problems, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

This article is intended as an educational aid and discusses guided wave propagation problems that are modeled via the Sturm-Liouville equation in electromagnetics. The bridge between source-free (eigenvalue) and source-driven (Green's function) problems that are represented by the same Sturm-Liouville equation is emphasized. The presentation focuses on representation of an arbitrary source from the features (eigenfunctions) of the problem geometry and extraction of the eigenvalues of a problem from propagation characteristics (Green's function) on a canonical problem; a homogeneously filled parallel plate waveguide with non-penetrable boundaries

A Pi Controller Based On Gain-Scheduling For Synchronous Generator, Alireza Sedaghati

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a gain- scheduling scheme of a proportional integral (GSPI) controller is proposed for a synchronous generator. In presented scheme, both proportional and integral gains are allowed to vary within a predetermined range. In order to validate the effectiveness of GSPI controller, simulation studies for a single-machine infinite bus power system are used .The results verify improved performance of GSPI controller comparing to conventional AVR under various operating conditions.

State-Space Synthesis Of Current-Mode First-Order Log-Domain Filters, Ali̇ Kirçay, Uğur Çam

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes current-mode first-order log-domain filters, which are systematically derived using the state-space synthesis procedure. First-order low-pass, high-pass, and all-pass responses are obtained with different circuit types. The filter circuits have very simple structures, since they use only bipolar junction transistors (BJTs) and a grounded capacitor. They can be electronically tuned by changing an external current. The filters have a greater bandwidth due to inherently current-mode and log-domain operation. PSPICE simulations are given to confirm the theoretical analysis.

Electrical And Computer Engineering Education In The 21^{St} Century: Issues, Perspectives And Challenges, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Infusing Technical Communication And Teamwork Within The Ece Curriculum, By April Kedrowicz, Sundy Watanabe, Damon Hall, Cynthia Furse

Turkish Journal of Electrical Engineering and Computer Sciences

This paper highlights a unique approach to infusing formal training and practice in oral and written communication and teamwork development in the Department of Electrical and Computer Engineering (ECE) at the University of Utah. Faculty and graduate (Ph.D.) students from the College of Humanities have teamed up with faculty from engineering to develop communication and teamwork instruction that is integrated into the existing engineering curriculum. These skills are used as a vehicle to provide better understanding of engineering concepts and their applications.

Secure Digital Communication Using Chaotic Symbolic Dynamics, Ajeesh P. Kurian, Sadasivan Puthusserypady

Turkish Journal of Electrical Engineering and Computer Sciences

One of the major hurdles in implementing chaotic communication schemes is the synchronization of chaotic systems. For the last two decades, numerous contributions of varying successes have been made by researchers from different disciplines for the synchronization of chaotic systems. Symbolic dynamics based synchronization method is shown to be capable of providing high quality synchronization (HQS), which is essential for reliable communication. In this work, using this method, a secure digital communication system is proposed. The well known piece-wise linear 1-D map such as tent map and Bernoulli shift map are used for this study. Since the information is dynamically …

Coalgebras And Their Logics, Alexander Kurz

Engineering Faculty Articles and Research

"Transition systems pervade much of computer science. This article outlines the beginnings of a general theory of specification languages for transition systems. More specifically, transition systems are generalised to coalgebras. Specification languages together with their proof systems, in the following called (logical or modal) calculi, are presented by the associated classes of algebras (e.g., classical propositional logic by Boolean algebras). Stone duality will be used to relate the logics and their coalgebraic semantics."

Observed Web Robot Behavior On Decaying Web Subsites, Joan A. Smith, Frank Mccown, Michael L. Nelson

Computer Science Faculty Publications

We describe the observed crawling patterns of various search engines (including Google, Yahoo and MSN) as they traverse a series of web subsites whose contents decay at predetermined rates. We plot the progress of the crawlers through the subsites, and their behaviors regarding the various file types included in the web subsites. We chose decaying subsites because we were originally interested in tracking the implication of using search engine caches for digital preservation. However, some of the crawling behaviors themselves proved to be interesting and have implications on using a search engine as an interface to a digital library.

Multi-Model Kalman Filtering For Adaptive Nonuniformity: Correction In Infrared Sensors, Jorge E. Pezoa, Majeed M. Hayat, Sergio N. Torres, Md. Saifur Rahman

Electrical and Computer Engineering Faculty Research and Publications

This paper presents an adaptive technique for the estimation of nonuniformity parameters of infrared focal-plane arrays that is robust with respect to changes and uncertainties in scene and sensor characteristics. The proposed algorithm is based on using a bank of Kalman filters in parallel. Each filter independently estimates state variables comprising the gain and the bias matrices of the sensor, according to its own dynamical-model parameters, which underly the statistics of the scene and the nonuniformity as well as the temporal drift in the nonuniformity. The supervising component of the algorithm then generates the final estimates of the state variables …

Statistical Adaptive Sensing By Detectors With Spectrally Overlapping Bands, Ünal Sakog ̆ Lu, Majeed M. Hayat, J. Scott Tyo, Philip Dowd, Senthil Annamalai, Kalyan T. Posani, Sanjay Krishna

Electrical and Computer Engineering Faculty Research and Publications

It has recently been reported that by using a spectral-tuning algorithm, the photocurrents of multiple detectors with spectrally overlapping responsivities can be optimally combined to synthesize, within certain limits, the response of a detector with an arbitrary responsivity. However, it is known that the presence of noise in the photocurrent can degrade the performance of this algorithm significantly, depending on the choice of the responsivity spectrum to be synthesized. We generalize this algorithm to accommodate noise. The results are applied to quantum-dot mid-infrared detectors with bias-dependent spectral responses. Simulation and experiment are used to show the ability of the algorithm …

Computation Of Bit-Error Probabilities For Optical Receivers Using Thin Avalanche Photodiodes, Byonghyok Choi, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

The large-deviation-based asymptotic-analysis and importance-sampling methods for computing bit-error probabilities for avalanche-photodiode (APD) based optical receivers, developed by Letaief and Sadowsky [IEEE Trans. Inform. Theory, vol. 38, pp. 1162-1169, 1992], are extended to include the effect of dead space, which is significant in high-speed APDs with thin multiplication regions. It is shown that the receiver's bit-error probability is reduced as the magnitude of dead space increases relative to the APD's multiplication-region width. The calculated error probabilities and receiver sensitivities are also compared with those obtained from the Chernoff bound.

Development And Delivery Of Coursework: The Legal/Regulatory/Policy Environment Of Cyberforensics, John W. Bagby, John C. Ruhnka

Journal of Digital Forensics, Security and Law

This paper describes a cyber-forensics course that integrates important public policy and legal issues as well as relevant forensic techniques. Cyber-forensics refers to the amalgam of multi-disciplinary activities involved in the identification, gathering, handling, custody, use and security of electronic files and records, involving expertise from the forensic domain, and which produces evidence useful in the proof of facts for both commercial and legal activities. The legal and regulatory environment in which electronic discovery takes place is of critical importance to cyber-forensics experts because the legal process imposes both constraints and opportunities for the effective use of evidence gathered through …

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.

Is Forensic Computing A Profession? Revisiting An Old Debate In A New Field, Bernd C. Stahl

Journal of Digital Forensics, Security and Law

Forensic Computing is a new and quickly developing field. It is in the process of becoming an academic discipline or sub-discipline with all the features from full undergraduate and postgraduate course provision to conferences and journals. An important question in this process of turning into an established discipline is whether it will coincide with the recognition of the graduates as professionals. This paper hopes to stimulate the debate as to whether forensic computing is or should be a discipline. In order to approach this question, the paper will discuss the concept of forensic computing including the most salient topics of …

Development Of An Ontology Based Forensic Search Mechanism: Proof Of Concept, Jill Slay, Fiona Schulz

Journal of Digital Forensics, Security and Law

This paper examines the problems faced by Law Enforcement in searching large quantities of electronic evidence. It examines the use of ontologies as the basis for new forensic software filters and provides a proof of concept tool based on an ontological design. It demonstrates that efficient searching is produced through the use of such a design and points to further work that might be carried out to extend this concept.

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.

The 2006 Analysis Of Information Remaining On Disks Offered For Sale On The Second Hand Market, Andy Jones, Craig Valli, Iain Sutherland, Paula Thomas

Journal of Digital Forensics, Security and Law

All organisations, whether in the public or private sector, use computers for the storage and processing of information relating to their business or services, their employees and their customers. A large proportion of families and individuals in their homes now also use personal computers and, both intentionally and inadvertently, often store on those computers personal information. It is clear that most organisations and individuals continue to be unaware of the information that may be stored on the hard disks that the computers contain, and have not considered what may happen to the information after the disposal of the equipment.

In …

Computer Forensics Field Triage Process Model, Marcus K. Rogers, James Goldman, Rick Mislan, Timothy Wedge, Steve Debrota

Journal of Digital Forensics, Security and Law

With the proliferation of digital based evidence, the need for the timely identification, analysis and interpretation of digital evidence is becoming more crucial. In many investigations critical information is required while at the scene or within a short period of time - measured in hours as opposed to days. The traditional cyber forensics approach of seizing a system(s)/media, transporting it to the lab, making a forensic image(s), and then searching the entire system for potential evidence, is no longer appropriate in some circumstances. In cases such as child abductions, pedophiles, missing or exploited persons, time is of the essence. In …

Hiring Process For Software Developers That Identifies Both Cultural And Technical Fit, David E. Berry

Seton Hall University Dissertations and Theses (ETDs)

No abstract provided.

Expanding Extracurricular Learning Opportunities Through International Engineering Student And Faculty Exchange, Mark Polczynski

Electrical and Computer Engineering Faculty Research and Publications

No abstract provided.

Tuple Space Coordination Across Space & Time, Gruia-Catalin Roman, Radu Handorean, Chenyang Lu

All Computer Science and Engineering Research

CAST is a coordination model designed to support interactions among agents executing on hosts that make up a mobile ad hoc network (MANET). From an application programmer’s point of view, CAST makes it possible for operations to be executed at arbitrary locations in space, at prescribed times which may be in the future, and on remote hosts even when no end-to-end connected route exists between the initiator and target(s) of the operation. To accomplish this, CAST assumes that each host moves in space in accordance with a motion profile which is accurate but which at any given time extends into …